7 Jul
2004
7 Jul
'04
10:39 a.m.
I have a sequence of functions that I wish to fold together using function composition (.). Does it matter if I use foldl or foldr? e.g. [[ sss :: [ShowS] sss = map (++) ["abc","def","ghi","jkl"] ssr = foldr (.) id sss ssl = foldl (.) id sss sr = ssr "" sl = ssl "" -- sl == sr == "abcdefghijkl" -- is there any efficiency difference? ]] Conventional wisdom suggests that foldr is better, but I'm not sure if it really matters in this case. #g ------------ Graham Klyne For email: http://www.ninebynine.org/#Contact